This invention relates primarily, but not exclusively, to a method of, and data storage medium adapted for, providing authentication of a data copy. It also relates, but not exclusively, to an electronic control device, for example a PC, adapted to sample a storage medium in order to authenticate the data thereupon and/or software to adapt the electronic control device to sample the storage medium.
Currently it is very simple to obtain a perfect copy of data recorded on digital media due to the proliferation of technologies such as, for example, CD rewriters. This has led to the massive growth of counterfeiting of computer software, DVD's and music CD's. Indeed in certain areas of the world there is virtually no genuine software, it is almost exclusively counterfeit.
Manufacturers of software and entertainment products currently have no convenient way of authenticating the data stored on a medium (e.g. a CD) in such a way that the authentication cannot be copied along with the data. This restricts the tracking of and quality control of products.
The ability of computers to copy data to floppy disks, the growth of MP3 players/recorders and the use of CD-rewriters to copy CD's, with no means of tracing the source data medium from which the data was copied and the machine used to copy the data, has resulted in the proliferation of untraceable copies of data.
U.S. Pat. No. 5,706,047 discloses an optical storage disc having a bar code in a mirror region of the disc. The code does not uniquely identify the disc.
U.S. Pat. No. 5,805,551 discloses a system for preventing illegal duplication from a CD or CD-ROM . On an optical mark section, there is recorded an ID number which is different at every disk. However, there is still a possibility of illegal printing. In order to improve prevention, a magnetic section is provided to record a magnetic ID number in the factory. A cipher to be recorded on the magnetic recording track is based on a mixture signal of the ID number, created by a unique ID number generator, and a disk physical arrangement (e.g. address, angular arrangement, tracking, pit depth, error rate) table, thus being different for every disk. First physical feature information and the different ID number are enciphered together. Accordingly, even if a disk whose password is known is obtained to replace the first cipher of this disk with the first cipher of another disk, operation is stopped because the physical information i.e. the original record is not the same. U.S. Pat. No. 5,805,551 does not disclose incorporating in the disk an electronically readable modification-resistant identifier for distinguishing the disk from other disks, which can be read from the disk in use.
WO 98/33176 A2 discloses a system for copy protection of recorded information. An information carrier comprises a medium mark representing a first bit pattern which cannot be copied on standard recording devices. The recorded information comprises a watermark representing a second bit pattern which has a predefined relationship to the first bit pattern. The medium mark indicates the status of the medium e.g. a code indicating a professional disk manufactured by pressing and is unique to a publisher or a title. Also, the recorded data is altered by the watermarking process.